Apparatus for edge joining plywood veneer sheets



June 14, 1960- R. A. MULLER 2,940,491

APPARATUS FOR EDGE JOINING PLYWOOD VENEER SHEETS si @H Ll o 1 3 N1202113241? l/llluier,

I Joadazey R. A. MULLER June 14, 1960 APPARATUS FOR EDGE JOINING PLYWOODVENEER SHEETS Filed Aug. l0, 1955 5 Sheets-Sheet 2 mm1@ o R. A. MULLERJune 14, 1960 APPARATUS FOR EDGE JOINING PLYWOOD VENEER SHEETS FiledAug. lO, 1955 5 Sheets-Sheet 3 R. A. MULLER `Fume 14, 196() APPARATUSFOR EDGE JOINING PLYWOOD VENEER SHEETS Filed Aug. 10, 1955 5Sheets-Sheet 4 June 14, 1960 R. A. MULLER 2,940,491

APPARATUS FOR EDGE JOINING PLYWOOD VENEER SHEETS Filed Aug. 10, 1955 5Sheets-Sheet 5 `of glue to these cut edges.

'United States 'latent O APPARATUS FOR EDGE J OINING PLYWOD VENEERSHEETS Robert A. Muller, New London, NH., assignor to Atlas PlywoodCorporation, Boston, Mass., a corporation of Massachusetts Filed Aug.10, 1955, Ser. No. 527,554

7 Claims. (Cl. 144-279) This invention relates to a method and apparatusfor fedge joining of sheet media such as plywood veneer sheets and, inparticular, relatively small pieces of plywood veneer which occur indifferent sizes and which are desired to be joined together andlaminated with rela.- tively larger sheets so as to effect importantsavings in dealing with waste stock from the manufacture of plywood. Itshould be understood that a conventional form of joining machine Wellknown in the plywood joining art may be employed to cut the variouslysized sheets with parallel edges and to apply a standard type Since theoperation of cutting and edge gluing is a common practice in the art, no.attempt is made to show such apparatus in the drawings lor to describesuch steps. Likewise, no attempt has been made to show or describe themethod and apparatus for laminating a joined length of material with topand bottom sheets, as this also is carried out by conventional apparatusand procedures ordinarily followed in making plywood.

At the present time, very considerable losses develop from the smallwaste ends which develop in making and utilizing plywood veneer.Inasmuch as these relatively small pieces of plywood occur in varyinglengths and widths, there has been, so far as I am aware, nosatisfactory way of properly combining the pieces to make usable largerpieces. A chief difficulty is found in holding the pieces together withtheir edges in abutting relation while exerting the necessary pressureand heat required to obtain a satisfactory jointed relationship of theconstituent pieces.

It is an object of the invention to devise a method and machine fordealing with the problem indicated. Another object is to provide atechnique for holding small sections or pieces of plywood in abuttedrelationship so that each piece may be subjected to compressive forceswhich act in two dimensions and which may progressively increase inmagnitude to reach a maximum in synchro- Anized relationship.

These and other objects and novel features will be :more fullyunderstood and appreciated from the following description of a preferredembodiment of the invention selected for purposes of illustration andshown in Fig. 2 is a transverse vertical cross-section taken ap- Fig. 7Vis a detail cross-section taken on the line 7-7 p yof Fig.V 6; and

2,940,491 Patented June 14, A1960 ice Fig. 8 is a diagrammatic view of adrive for the machine. t

. As one way of satisfactory exerting compressive forces which act on asheet material in two dimensions sirnultaneously, I have devised aunique combination of driving wheels and vertically adjustable pressmechanism by means of which I am enabled to produce controlled forwardmotion of the sheet media. vDuring this forward motion, verticallydirected compressive forces are built up to reach a maximum in timedrelationship with the development of horizontally acting compressiveforces which approach their maximum value at approximately the point ofmaximum intensity of the vertically exerted forces.

In the structure shown in Ithe drawings, numeral 10 denotes an elongatedframe or raised table for supporting the plywood handling mechanism ofthe invention. This frame is shown in Figs. l and 2 and on a somewhatsmaller scale in Fig. 6. As noted in Fig. 1 at the letthand sidethereof, I provide conveyor means which may, for example, consist of aplurality of endless belts 12, 14, 16, 18 and '20 led around pulleys as11, 13, 15, 17, 19 and 21. A table 22 is mounted on the frame in aposition to tirmly support the belts. This conveyor arrangementconstitutes an assembly table on which may be located a plurality ofpieces of plywood as suggested by the arrows P, P' shown in dotted linesin Fig. l, and occurring with their adjacent edges arranged in abuttingrelationship. When the conveyor -belts are driven, the pieces of plywoodare advanced along a horizontal path of movement into engagement withand between pairs of upper and lower driving rolls as A and B, C and D,E andA F, and G and H. Each pair of rolls is horizontally spaced apartfrom an adjacent pair of rolls, as shown in Figs. 2 and 3. The severalpairs of rolls noted are mounted on respective upper and lower shafts as24 and 26, which are supported for rotation between the two sides of theframe in suitable bearings 24a and 26a (Fig. 2). As shown in Fig. 4,each set of rolls A mounted on the shaft 24 comprise also the rolls A1,A2, A?,v and A4. The next set of upper rolls C comprise also the rollsC1, C2, C3 and C4 mounted on the shaft 23. Additional sets of rolls Eand G are mounted on the shafts 27 and 31 and comprise the rolls E1, E2,E3 and E4 for shaft 27 and rolls G1, G2, G3 and G4 for shaft 31. Thelower set of rolls, four in number, B, D, F and H (see Fig. 3), compriseve rollsV on each shaft corresponding to the upper rolls previouslydescribed.

At theouter ends of the shafts 31 and 33 are bevel gears as 2S and 36which are in mesh with bevel gears as 32 and 34 on respective shafts 36and 38. Similarly, shafts 27 and A29, 23 and 25, and 24 and 26 aredriven by bevel gears as 40, 42, 44, 46, 48, 50.` As may be seen from aninspection of Fig. l, all of these gears are actuated by a sprocket 60and chain 62 which is power driven from a motor M operating through asingle revolution clutch K and a Reeves drive L, together with sprocketchain and .sprocket gears as shown. All of the upper shafts 23, 24, 27and 31 are secured on vertically adjustable mounts which carry theshafts 36 and 38 4so `that the entire set of upper rolls may be adjustedtowards and away from the lower rolls to move into rolling contact withplywood sections passing therebetween, a single section of which hasbeen shown in Fig. Zand denoted by the reference character P3.

In accordance with the invention, I further provide for each successiveset of upper Iand lower rolls being constructed with progressivelysmaller diameters going from the in feed to the out feed. Thus, rolls Gand H, as well as all other rolls in this set of rolls are formed withthe smallest diameter. Rolls E and F and similar rolls in this set areconstructed with a slightly larger diameter.

Y #Rolled -compte sson for@ Z011 RlYWQQd -CEQIISA at ngilzltsoburring'between th'A ad'B'roIls Vand the 'Grandi-I 5 material occuringbetween itseif and the lower set ofV nd'ba'se plates .574, 75, 75,",7-7l.in turn/@received on angle 11,1 in forfproducingta verticalpscilllfipiitifbulgharyery Y ,u ts.

A:l'y'fisec'niredin somers'uitablemanner, Yas by bolts, welding weasel'of the arrangement described, Ithe air cylinders, when actuated, mayVoperate to vlift "the entire upper press and -mll assemblysimultaneously and then to release this whole unit so that its weightmay come to bear against sheet Likewise, C and D rolls are longer andArand B rolls Y are made With the' greatest diameter. 'By meansV of thisarrangement, I nd that-I am enabled to exert a conpress units. t

Normally, the upper pressfunit may be located in a fully leitete@@stiften Yand @l may desire ,te ,mende stop means as Z, as suggested kinEig. ,6, to vary the exact weight condition which is allowedtogbeegrertedpn Work nrs'sfingttie thelmahrjis- TQS @ist vertige;instmentV may bepermanently set and thereafterethe Abine is operatedWithout changing this setting fora given set of requirei'nents.L

Considering secondly Ytheverticalll-y, oseillatable means for the upperset of' presses, attentioil'is again directed to Figs. 2, 4 and 5wherein I have shown means for peri- Sid'vf'fliemhe she. llnsliall, 29.and 2i Y y f sflmll vTlfise beatings 911 theres@ ve beamsves`Attjention is directed to Fig. 2 in which the details of 110, assuggested in 'Fg'. 'ZQ'Wth only twqpails of bear,-costrction'ofthepresses maybe more elealy seen. As Yings having beenincluded 'in the drawings but which are shown therein, Ithere Yare fourlower press units `and `four 30 intended to constitute a diselosure ofany other reqlrd upper press units 1and the several .units arevtransversely number forvdealing with eaehof theindividnal press unitsspaced apart'toconveniently loccupyj'w space between where is required'.The 4shafts as 109 are driven :by theupper andlower driving rolls."Ihe'lowertpres's somesliitable means, vsuch foregample, SPlQket gearsare Ydeiziotedibyi thenumefralslo', Y71,7Z2and 73tand these as 1.50,152" and chain 154, diagrammatially indicated Vare 'Supported in la`stationary position :on brackets 35 v'at-the' ifightlhand side o f. Fig .'2 .`4

i' `O Y 'theseshafts at spacedfinteivgisbetween the bearings noted areied cams '25112, 1'14, etc, 'Thesercanls Vare in tolling seneaemee? en@Slipnqrhttlsreoarespsrocm' fp'llbwefs as pmi, 11i' neem niveau rep'eivdiires 'saffier @its VWL (..Fis- 4Y end Olies'f fhd Y, S ASill/(W13.iii mbe detfll Fig, 5-

iwted infie-"Silbe .cam :followers 4are summed,

11D llfi f lh@ IiI-WgfwhaYIl-QSlUISibIQ i againstilielndersids;Ofthplywod Sectins "they .pfass'lgetween the' r'folls'.Qonmncatig for exampleon'pinsas 115'1eceiv1ed throughtw pacjd- `theinterior' .of of' the pfress enclosures lare steam apart sides 160, 162of the carrier unit (Fig. 2)'. redness which a@ @me meisten-@Pili 45'enea ,between fue side elements man@ 1612 @wie Q heat Pr-SGS t0 a.vsird temperature. A as fli'and 166 whicbareconnected at their uplerTheuRperprless'nnitsar of thesamelreetangular shape '.bya harnasY 16S",(Fig'sQZ and 5).l A n adjustment andfaresimilarly provide`withetceteraheads l vsc w":170 isthreaded through the bar '168, asshownin t *Pipes sito Ptslide off-.eltableheafilie Hemer,

'el and ennemie-1eme@ r; s 'trokeepdisp1acemem-i el@ #991 the lewe: endssi the nsidine -rsi the vertical lfrmehanism, I provide 16 :166 arelongitudinally .ext ding tangle iron `se glilrlmy'proyidea pair oftransverse I-beams, sueh Yzittzftchedto l lseccindsetof angle ironSectio 131),? 131 beanisll'() as's'hown in.Fig. l2. These' .two beams 134 and 136 whichfinclude shoes13th,"132e,VA a and .arelocated atzoppositeends .of the machine and are solid- 60 136g having at"'bot'tom"surfacsadapted t'ocorne into contactv with rthe n,sides "of resg'ectivenn "er iunits,Y as will i?? ilitnt' from ininspio 4' migas ierand'lwb, armingeen the machine frame. .Secured to the underside of Theifconnection o'fthe lsides 164 'and 166 ,ofthe carrier missili? einem@ S-,indetd @figs 3and 6, unit V t0 the longitudinal member 13.4' ise l'a'y lef-Mse numberQf air sylinder 'units of 65 'idica'ted' iFie-S Farid, las "noen' thatTg'ur, 'the nugentional two of whichlhave .beentnot'edin the sides maybe separated hybrid ngffiiecesjf'bt,add espy ghenvmrelslzaqd un. Theseair eyiinf figidityfethe Seneffe: Umts have depending threftpn;lift-.rosliandl i It will be observedthat theseglengitudnauy extendingllgfagg-,Ht Speiallyformed channels-31.1 respective ann which then moveup into contact with the transverse beams 100 and lift the entire pressassembly through a short vertical path of travel.

In accordance with the invention, the operation of the shaft 109 istimed with respect to the operation of the shafts for the driving wheelsor rolls described above, so that a maximum vertical pressure may beexerted through the several shoes 130:1, 132:1, 134a and 136:1 atdesired points in the interval of travel of abutting sections of sheetmaterial passing through the machine and, in particular, at the pointwhere a maximum force iu compression is acting horizontally through theabutting sheet material sections so that these sections can bemaintained in an undistorted horizontal plane while abutting edgesreceive the necessary pressure and heat delivered from the presses toachieve an extremely strong bonding together of these edges. It willalso be observed that this method and apparatus for exerting forces ofcompression in the sheet material sections operates to produce periodicmaximum compression conditions adapted to cooperate with the heatingwhich is furnished by the presses while in contact with the work pieces.Because of these flexible features, it is pointed out that a wide rangeof widths of sections may be continuously placed on the conveyor end ofthe machine and continuously fed through the driving rolls to bereleased upon the conveyor at the right-hand side of the machine, asshown in Fig. 1.

From here, the stock may pass to a sizing mechanism such as, forexample, is comprised by edge saws 180 and 182 which are driven from amotor 184 through a conventional sprocket and chain drive, as suggestedin Fig. l. A nished piece of stock 186 is shown leaving the sizingmechanism at the right-hand side of Fig. l after having been joinedalong aline of abutment 188.

From the foregoing description of my invention, it will be evident thatI have provided an eicient and rapid method for edge joining sections ofsheet material and particularly sections of plywood veneer which arerequired to be held very rmly and to be subjected to the action of bothheat and pressure in two dimensions. It will also be seen that I haveprovided a unique mechanism for carrying out the method of the inventionand exerting simultaneously both vertically and horizontally directedforces of compression which build up to a maximum in timed relationshipand yet permit stock which has been compressed and joined to pass alongin a substantially uninterrupted path of travel.

The apparatus described is intended to constitute one suitable means forcarrying out the method of the invention. However, it is intended thatthis apparatus may be modified in various respects to accomplish thepurposes and functions described in accordance with the scope of theclaims appended thereto.

I claim:

l. A machine for edge joining plywood veneer sheets comprising a frame,conveyor means mounted in the frame at the front end thereof forhorizontally supporting a plurality of plywood veneer sheets with theiredges in abutting relationship, upper and lower driving rolls rotatablymounted between the sides of the frame for engaging the veneer sheets attransversely spaced-apart points and advancing them along a horizontalpath of movement, said upper and lower rolls having their diametersprogressively reduced to provide continuously exerted forces ofcompression acting in the direction of the path of travel of the veneersheets, and vertically adjustable platens movable in timed relation intoand out of engagement with the sheets during the period in which theyundergo horizontal forces of compression by said upper and lower rolls.

2. A structure according to claim 1 in which the platens for exertingvertically directed prsure consists of a series of hollow upper andlower platens.

3. A structure according to claim l in which the platens are locatedbetween the upper and lower driving rolls.

4. A structure according to claim 3 in which the platens are heated.

5. A machine for edge joining plywood veneer sheets comprising a frame,upper and lower spaced apart driven rolls rotatably mounted in the sidesof the frame for engaging the veneer sheets in transverse spaced apartpoints and advancing said sheets along a horizontal path of movementbetween said rolls, the upper and lower rolls each having theirdiameters progressively reduced to thereby provide continuous exertedforces of compression acting in the direction of the path of travel ofthe veneer sheets and upper and lower platens mounted in a horizontalplane occupying the spaces between the driven rolls.

6. The structure according to claim 5 in which the platens are hollowand are heated.

7. The structure according to claim 5 in which the upper platens areperiodically lowered and raised in timed relation to the upper surfaceof the plywood sheets.

References Cited in the le of this patent UNITED STATES PATENTS2,344,488 Bowling Mar. 21, 1944 2,366,588 Bolling Jan. 2, 1945 2,371,331Irwin et al Mar. 13, 1945 2,373,376 Bolling Apr. 10, 1945 2,544,133Carlson Mar. 6, 1951 2,644,496 Schubert July 7, 1953 2,739,628 Kok Mar.27, 1956

